This section is from the book "The Building Trades Pocketbook", by International Correspondence Schools. Also available from Amazon: Building Trades Pocketbook: a Handy Manual of reference on Building Construction.
The ratio between the width and height of doors at main entrances and in public buildings is usually as
1 to 2; that is, the height is twice the width. For single doors in dwellings and offices, the ratio should be as 1 to 2 1/2; or the height should be 2 1/2 times the width; doors 2' 8" X 6' 8" and 3' X 7' 6", are thus proportioned.
The width of a door is regulated by the purpose for which it is intended; in public buildings provision is made for the passage of several persons at a time, while in private houses and offices a width suitable for one person is sufficient. In the former case, the width may be from 6 to 14 ft., while in the latter, the general rule makes the minimum width
2 ft. 8 in. for communicating doors, and 2 ft. for closet doors. A hinged door more than 4 ft. wide should be made double; that is, in two folds. As double folding doors take up much wall space when kept open, sliding doors are frequently substituted. Where there are several doors of different widths in the same room, to give a better effect to the interior treatment the height of the principal doors should be fixed by the proportion given, and the others made the same height. If the width of double or sliding doors does not exceed 6 ft., the -height may be that of principal doors, but if wider, the height should be one-fourth more than the width. The width of sliding doors, however, is largely regulated by the depth obtainable for the pocket in the partition.
The width of the stiles and top rail should bo about one-seventh the width of the door, the bottom rail about one-tenth the height, and the muntins and lock-rails 1/2 in. less in width than the stiles. The thickness will depend somewhat on the style of finish and the class of lock to be used. If the door framing is solid and rim locks are used, the thickness for chamber doors may be 1 1/4 in.; if mortise locks are used, the thickness should not be less than 1 1/2 in. Solid doors for principal rooms are made from 1 3/4 in. to 2 in., and entrance and vestibule doors from 2 1/4 in. to 2 1/2 in. thick. When doors are veneered, the thickness is usually increased 1/4 in.
When mortise locks are used, the doors should, for strength, be framed with a lock-panel so that the joints adjacent to the lock will not be injured.
The mode of constructing a 5-paneled door is shown in Fig. 20, certain parts being removed to clearly show the joints. The parts marked a are the outer stiles; b, the muntins; c, the bottom rail; d, the lock-rails; e, the top rail; f the lower panels; g, the lock-panel, and h, the upper panels. The mortises i are made one-third the thickness of the framing into which the tenons j are fitted. The edges of the framing are grooved 1/2 in. deep, to receive the panels, the width of the groove being the same as the thickness of the tenon. The upper edge of the tenons of the top rail and the lower edge of the tenons of the bottom rail are haunched, as shown at k. The bottom rail has double tenons with, a bridge between the mortises. The muntins are mortised into the rails. The panels should be kept from 1/8 to 3/16 in. less than the width of the space between grooves, to permit expansion.
In putting the door together, only the shoulder, or that portion of the tenon next the panel, should be glued, so that in case of shrinkage or swelling the joints will remain close. When the stiles are driven up and the clamps applied, the wedges I should be well fitted, should have the edges next the tenons brushed with glue, and be driven tightly in. The horns m, or extra lengths of the stiles during construction, are designed to withstand the pressure exerted when the end wedges are driven in, which would otherwise be forced out by shearing the fibers of the wood beyond the mortise, thus destroying the joint.